Uncapped Quinn Roux and Sean Reidy have been named in Ireland's 32-man squad for the tour of South Africa, while Leinster backs Garry Ringrose and Ian Madigan miss out.
Ireland take on the Spingboks in three Tests on consecutive Saturday’s starting on 11 June in Cape Town.
Ulster out-half Paddy Jackson comes back into the fold with Bordeaux-bound Madigan not included.
Jackson's team-mate Stuart McCloskey, who made his debut during the last Six Nations, is not included.
Connacht second row and South Africa native Roux and Ulster back row, New Zealand-born Reidy, have done enough in recent Pro12 games to impress head coach Joe Schmidt.
There is no place, however, for Munster's Tommy O'Donnell, who won the last of his 12 caps in March against Scotland.
Schmidt said: “Touring South Africa will be arduous to say the least so we've attempted to prioritise players who are currently as close to full fitness as possible.
“In what is always a difficult balancing act, we've taken a long term view with a number of players who need a rest or will benefit from a full pre-season.”
Leinster centre Ringrose, who will be in action for the Blues in Saturday’s Pro12 final against Connacht in Edinburgh, had trained with Ireland during the Six Nations campaign but has not made the cut.
Not considered due to injury were forwards Cian Healy, Denis Buckley, Nathan White, Josh van der Flier, Peter O'Mahony, Sean O'Brien, and backs Tommy Bowe, Andrew Conway and Simon Zebo.
Ireland Squad
Forwards (18)
Finlay Bealham (Corinthians/Connacht)
Rory Best (Banbridge/Ulster) (c)
Sean Cronin (St Marys/Leinster)
Ultan Dillane (Corinthians/Connacht)
Tadhg Furlong (Clontarf/Leinster)
Jamie Heaslip (Dublin University/Leinster) (vc)
Iain Henderson (Ballynahinch/Ulster)
David Kilcoyne (UL Bohemians/Munster)
Jack McGrath (St Marys/Leinster)
Jordi Murphy (Lansdowne/Leinster)
Sean Reidy (Belfast Harlequins/Ulster)*
Mike Ross (Clontarf/Leinster)
Quinn Roux (Galwegians/Connacht)*
Rhys Ruddock (St Marys/Leinster)
Donnacha Ryan (Shannon/Munster)
CJ Stander (Munster)
Richardt Strauss (Old Wesley/Leinster)
Devin Toner (Lansdowne/Leinster)
Backs (14)
Keith Earls (Young Munster/Munster)
Luke Fitzgerald (Blackrock/Leinster)
Robbie Henshaw (Buccaneers/Connacht)
Paddy Jackson (Dungannon/Ulster)
David Kearney (Lansdowne/Leinster)
Rob Kearney (UCD/Leinster)
Kieran Marmion (Corinthians/Connacht)
Luke Marshall (Ballymena/Ulster)
Conor Murray (Garryowen/Munster)
Stuart Olding (Belfast Harlequins/Ulster)
Jared Payne (Ulster)
Eoin Reddan (Old Crescent/Leinster)
Jonathan Sexton (St Marys/Leinster)
Andrew Trimble (Ballymena/Ulster)
*uncapped
